Firing mechanism barrier



Nov.28,1944. w. ETHIBQDEAU ETAL 2,363,562

FIRING MECHANISM BARRIER Filed Jan. 24, 1941 2 Sheets-Sheet l IIID I lmd/ 2; za I INVENTORS W/ lfred E. Thlbodeau AT /RNEY NOV. 28, 1944. w THlBODEAU ETAL 2,363,562

I FIRING MECHANISM BARRIER Filed Jan. 24, 1941 2 Sheets-Sheet 2 iIlllllHE I'IIIA Graver-q J. Hesse I #vw Q WM ATTO R N EY Patented Nov. 28, 1944 UNITED STATES PATE T OFFICE Wilfred E. Thibodeau,

Gregory J. Kessenich, Madison, Wis.

Application January 24, 194L S erial No. 375,800

7 Claims. (Cl. 192-79) (Granted under the act of March 3,1883, as

amended April 30, 1928; 370 O. G. 757) v The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to us of any royalty thereon.

This invention relates to projectile fuses and in particular to a new type of safety member for the same.

Broadly, the invention consists in providing for the primer in a fuse, a protective member of material which is soft-rubber-like in its physical properties such as resilience and high elastic deformation. Any natural orsynthetic rubber maybe used, or any other rubber-like product of the general type of polymerized hydrocarbons having elastic properties similar to soft rubber. Such a material will undergo tremendous changes in shape or form under the action of centrifugal force at bullet rotational velocities and such changes can be utilized to place a fuse in armed,

condition. This form of fuse can return to unarmed condition after rotation has abated, and

during the interval represented by such ranges.

It is therefore an object. of this invention to provide a fuse having a safety member of a material soft-rubber-like in its physical properties, so utilized in the fuse as to deform under centrifugal force to arm the fuse.

It is another object of the invention to provide a fuse as above which will also be unarmed on abatement of rotation.

1 To these and other ends, the invention consists in the construction, arrangement and combination of elements described hereinafter and pointed out in the claims forming a part of this specification. 1

A practical embodiment of the invention is illustrated in the accompanying drawing where- Figure 1 is a sectional view in elevation of the forward portion of a shell, showing the fuse structure;

Figure 2 is a sectional view on the line 2-2 of Figure l;

Figures 3 to 8 and 10 are views similar to Figure 1 showing modifications;

Figure 9 is a sectional view on the line 9-9 of Figure 8, and

Figures 11 and 12 are perspective views of modifications of the rubber blocking member.

Referring to the drawing by characters of reference, there is shown inFigure l a projectile Cleveland, Ohio, and

body I having threadedly attached thereto a nose cap 2. Within the body l is an axial bore 3, and, at the base thereof, a smallerbore 4 to accommodate 'a primer 5. Cap 2 has an axial bore 6 slidably receiving a firing pin 1. Pin 1 may be held in the shellby turning over the edges of bore 6 as at 8. Fitted between a shoulder 9 of the pin 1 and the primer and'surrounding the point of pin 1 is a thick rubber tube Ill. Surrounding the rubbermember in contacting relation andsnugly fitting the bore 3 is a cagelike insert consistingof washer-like end members H with rodelike uprights I2 aflixed thereto. The'particular shape of this cage is not critical since any device which williengage the rubber at peripheral points of the latter on dilation will answer the purpose. The rod |2 may be rectangular or any. othershape in cross-section and may be integral with the end pieces, or rods l2 may be integral with any part of the fuse, thuseliminating the, end pieces II.

On rotation, the rubber commences to distend into the spaces. is between rods l2, the rods serving to maintain the rubber in rotation. On distension, the central hole I4 in the rubber opens to free the pin 1. If no impact Occurs the rubber will eventually return to safe position.

Referring to Figure 3 there is shown a fuse havinga shell body portion l5 and a nose cap it threadedly attached thereto. Through cap [6 and into body I5 is a bore 1! and slidably fitted in bore :1! is a firing pin IS. A primer I9 is located in a recess at thebottom of bore ll. Complementary recesses in the cap I6 and body [5 define a U-shaped annular channel 20; Inserted in the bodyat intervals around the recess and extending across the channel are pins 2|. Inside the circle of "pins 2| and extending into a groove 22 in the pin [8 is a rubber band 23 of circular section. This rubber member may also be rectangular in section, or any other convenient shape. Theresistance to shear of the rubber member will hold the firing pin safe under all ordinary conditions, but on rotation the rubber member will distend into the channel and free the pin. 1

In Figure 4 is shown atprojectile 24 having threadedly attached thereto a nose cap 25. The cap has an outer bore 26 inwhich ,a firing pin 21 is slidably fitted and an inner tapering bore 28. A primer carrier 29 is threadedly or otherwise attached inthelower opening of the tapered bore28. Firing pin 27 hasa bevelledshoulder 30; and between this shoulder and the tapering fications of the pin are shown in Figure 4. On

the left the pin is shown as movable forward of the fuse, while on the right the pin is shown as held against forward motion.

In Figure 5 there is shown a projectile body '33 having threadedly attached thereto a nose cap 34. The cap and body portions have compleopen spaces 62 in its periphery to allow for distensionon rotation. Perforations 63 in the body may also allow for distension.

We claim:

1. A fuse comprising a casing, a firing element and a barrier for said firing element in said casing, said barrier consisting essentially of a material with elastic properties similar to those of soft rubber and having a portion of its outer boundary spaced from the casing, said barrier constructed and arranged in said casing for vol- .ume distortion and a resultant distension of said portion of its outer boundary radially of the fuse mentary circular grooves and 36 respectively defining, when juxtaposed, an annular channel of generally hourglass section with a constricted -:a material withelastic properties similar to those portion 31. Cap 34 and body 33 have axial bores 38 and 39 resp ctively. Cap bore 38 has fitted therein the head '40 of a firing pin4l, and body bore 39'has fitted therein a primer 42. Fitted between the primer and the head .40. of pin 4| and surrounding the shank of the latter is a perf rated rubber cylinder 43.- This perforated cylinder'has its outer periphery located in the openin'ginto the channel. On rotation the rubber member Willdistend and be forced through the constriction 31 and into the outer chamber of 1 the channel where it will remain trapped. I

In Figure 6 is shown a'projectile body 44 hav-' 7 ,ing an axial bore 45 opening forward thereof, a

firing pin 43 slidably held in the bore, and a primer 41 fixed in the base of the bore. Extending through lateral bores 48 and intercepting the pin 46 are rubber centrifugal bolts 49. Lateralbores 48 are preferably tapered so as to flare outwardly. This type of fuse resembles a wellknown type-wherein metal centrifugal bolts are used, but the employment of rubber centrifugal bolts represents an improvement thereover, since they can be securely jammed into the bores and yetbe easily loosened under centrifugal forcedue to volume-flow. In other words, advantage is taken of theproperties of rubber wherebyit :par-

' cient to hold the-pin from contacting the primer under the shocks incident to ordinary handling. However, upon rotation, the rubber tube will distend into groove 52 thus eliminating direct columnar support and the pin will easily flex thev distorted tube on impact, to fire the primer,

In Figure 8 isshown a fuse with a cylindrical tube rubber barrier 51 with longitudinal corrugations. In this case centrifuging distends the troughs 58 of the corrugations to free the pin 59. In Figure 10 is shown a fuse similar to that of Figure 8 except that in this case the corrugations 60 are circumferential instead of'longitudinal. Here the pin 6| is movable in ordinary'ha'ndling but is limited to fall short of the primer when the rubber is subjected to compression alone. Upon rotationthe path to the primer cleared.

"InjFigures '1'1 and 12 areshown rubber barriers of stellate form designed to fit withtheir radial extremities 'into'a cavity in a fuse, but having axis under the urging of centrifugal force.

andia barrier for said firing element in said'casing, said barrier member comprising essentially .of soft rubber, said barrier being coaxial with said casing and axially perforated, said barrier constructed and arranged in said casing fordistension of at least a portion of its outer boundary radially of the fuse axis under theurging of cen trifugal force, and means on the casing and contacting the barrier to rotate the barrier in uni son with the casing.

3 A fuse asin claim 2 in which said contacting means comprise rod members arranged. ldngitudinally of the casing andcontacting the barrier at radial extremities thereof.

4. A fuse comprising a casing, a firing element and a barrier member for said firing element in said casing, said barrier member consisting-ea sentially of a material with elastic properties similarto those of soft rubber, said barrier member being coaxial with said casing and axially perforated, said barrier member having at least a portion of its radial periphery spaced from the sides of said casing and other portions thereof contacting the sides of said casing to allow for distension of the barrier member radially of the fuse axis consequent upon its volume distortion under the urging of centrifugal force.

5. A fusecomprising a cylindrical casing with an annular groovein the inside wall thereof, a

firing element and a barrier member forsaid firing element in said casing, said barrier. member. being of tubular form and fitted snugly into the casing, said barriersmember comprising essentially a material with elastic properties similar to those of soft rubber, whereby the barrier member furnishescolumnar support to resist motion of the firing element, but, under the urging of. centrifugal force, distends into said annular grooveto weaken the columnar support and per. mit fl xin thereof and consequent displacement ofthe firing element, g

6. A fuse comprising a casing, a firing element and .a barrier for said firing element in said casing, said barrier member consisting essentially of a material with elastic properties similar to those of .soft rubber, said barrier being coaxial with said fuse and axially perforated, said barrier occupying less than the Whole of the cross section of said casing whereby, consequent uponit's volume distortion upon rotation, it can "distend unblock said member. v

WILFRED THIBonEAu. GR-EGORY' J, K-ESSENICH."

2. Afuse comprising a casing, a firing element 

